The majority of the world's population now lives in metropolitan areas. When living in these large, populous places it can be difficult to escape the constant presence and noise of other human beings. The noise created by others can cause a problem in a wide variety of ways, from the inability to enjoy relaxed recreational time (e.g., watching a movie in your living room) to increased difficulty when trying to accomplish a task that requires a great deal of concentration (e.g., complex work in an office space).
Although the problem may exist outdoors in large crowds, most people are not trying to escape to peace and quiet while in a crowded environment. Thus, the effect of being unable to enjoy a quiet space is typically more pronounced indoors. For example, it may be difficult to work in an office environment when playing music or talking loudly takes place in an adjacent room. Additionally, a user may wish to create a more private and comfortable living environment within an apartment complex. Thus, the general quality of life enjoyed by most people could be greatly improved with a mechanism for reducing the effects of intrusive noises within an area.